TGFB1 and neoplasm: Consistent with previous work8,13,44, we found that combining therapeutic anti-PD-L1 with anti-TGFβ treatment (a monoclonal antibody that neutralizes all three active TGFβ isoforms) promoted tumor regression and survival in the immune-excluded EMT6 tumor model compared to control and single agent treatments (70% or more complete responders in combination treatment compared to ~30% in anti-PD-L1, Fig. 1a, b and Supplementary Fig. 1A).